List-I (Precipitating reagent and conditions) | List-II (Cation) |
---|---|
(A) \(NH_4Cl + NH_4OH\) | (I) Mn2+ |
(B) \(NH_4OH + Na_2CO_3\) | (II) Pb2+ |
(C) \(NH_4OH + NH_4Cl + H_2S gas\) | (III) Al3+ |
(D) dilute HCl | (IV) Sr2+ |
The matching is based on the chemical properties and specific precipitation conditions for cations:
[A.] NH$_4$Cl + NH$_4$OH precipitates Al(OH)$_3$, hence matches with III. Al$^{3+}$.
[B.] NH$_4$OH + Na$_2$CO$_3$ precipitates SrCO$_3$, hence matches with IV. Sr$^{2+}$.
[C.] NH$_4$OH + NH$_4$Cl + H$_2$S gas precipitates PbS, hence matches with II. Pb$^{2+}$.
[D.] Dilute HCl precipitates MnCl$_2$, hence matches with I. Mn$^{2+}$.
Thus, the correct order is:
\[A -- III, B -- IV, C -- II, D -- I.\]
Among the following cations, the number of cations which will give characteristic precipitate in their identification tests with
\(K_4\)[Fe(CN)\(_6\)] is : \[ {Cu}^{2+}, \, {Fe}^{3+}, \, {Ba}^{2+}, \, {Ca}^{2+}, \, {NH}_4^+, \, {Mg}^{2+}, \, {Zn}^{2+} \]